New fridges will likely be greener. In a switchover that will be largely invisible to consumers, more fridges and air conditioners are entering the U.S. market that will do less harm to the planet.

This week, the U.S. government took a step to expedite that rollout. As part of President Barack Obama's climate plan and ahead of global climate talks, the Environmental Protection Agency approved five less-polluting chemicals or refrigerants, one of which is flammable propane.

"We can turn the challenge of climate change into an opportunity to innovate our way to a better future," EPA Administrator Gina McCarthy said in announcing the final rule, which applies to fridges, freezers, vending machines, and window AC units.

EPA's rules often give the industry heartburn—but not this one. Companies are on board, knowing time is running out for refrigerants such as hydrofluorocarbons (HFCs) that pose a rapidly growing climate threat. These coolants—used in cars and buildings—emit heat-trapping gases during manufacturing, leakage, or disposal.

History shows that a solution to one problem, however, may exacerbate another. HFCs, for example, are a third-generation coolant that have largely replaced earlier ozone-depleting chemicals such as R-22, commonly known by the brand name Freon.

HFCs are safer for the ozone layer but not necessarily for the planet. They're nearly 10,000 times as potent as carbon dioxide. Unless their growth is checked, their emissions could double by 2020 and triple by 2030, according to U.S. data.

On Friday, at an environment conference in Cairo, Egypt, 54 African countries called for a phase down of HFC—a position backed by the United Nations Enivronment Programme's executive director Achim Steiner.

“Though HFCs currently represent a small fraction of the total greenhouse gas emissions, their global-warming-potential is very high, and their emissions could rise even up to 40% of annual carbon dioxide emissions by the middle of the century if society continues,” Steiner said in a keynote address at the meeting.

The U.S. is not banning HFCs—at least not yet—but advocating cleaner alternatives. EPA's new suggested refrigerants have much lower global-warming potential, a measure of the heat that a greenhouse gas traps in the atmosphere. These range from 3 to 675, compared with 1,400 to 4,000 for older compounds they'll replace.

Will homeowners be affected? They may not even notice, says Drusilla Hufford, director of EPA's Stratospheric Protection Division. Hufford says prior shifts in coolants, whether in cars or buildings, have been so seamless that they've been "invisible to consumers."

Newer refrigerants won't likely increase prices much, if at all, says Dietz, whose group represents manufacturers of central air-conditioning systems. He says its members have not expressed concerns about rising costs.

As a result, consumers might pay higher prices for R-22. And propane, one of the newly approved refrigerants, is too flammable to be used safely in some ACs.

The EPA's Hufford says "a proliferation of incidents" have occurred in which flammable refrigerants have been used in non-flammable units. She adds: "We know they can be used safely" if they adhere to federal guidelines.

Consumers don't necessarily have to wait for a new AC system to make theirs greener.

"If you notice your home or car AC isn't working as well as it used to, get it professionally serviced," says Emily Davis, an attorney for the Natural Resources Defense Council, an environmental group. She says a technician can fix any leaks and may be able to suggest a safe, cleaner refrigerant replacement.

"I see this as an opportunity for consumers," Davis says of the coolant switchover, adding it offers them a "clear action" they can take to help protect the environment.